1. Field of the Invention
The present invention relates to a heat dissipation device, and more particularly to a heat dissipation device which can more effectively dissipate heat on the device by air convection, wherein the device is used for mounting a light emitting device module thereon.
2. Description of Related Art
A light emitting diode (LED) is a device for transferring electricity to light by using a theory that, if a current is made to flow in a forward direction through a junction region comprising two different semiconductors, electrons and holes are coupled at the junction region to generate a light beam. The LED has an advantage in that it is resistant to shock, and has an almost eternal lifetime under a specific condition, so more and more LED modules with different capabilities are being developed.
LED modules for use in a display or an illumination device require many LEDs, and most of the LEDs are driven at the same time, which results in a quick rise in temperature of the LED module. Since generally the LED modules do not have heat dissipation devices with good heat dissipating efficiencies, operation of the general LED modules has a problem of instability because of the rapid buildup of heat. Consequently, the light from the LED module often flickers, which degrades the quality of the display or illumination.
As LED technology continues to advance, more and more heat dissipation devices are applied to the LED modules for dissipating heat from the LED modules. A related heat dissipation device attached to an LED module usually comprises a heat sink having a base and a plurality of fins mounted on the base. The fins are located parallel to each other and perpendicular to the base. A plurality of channels is defined between the fins of the heat sink and arranged parallel to each other. Through a natural air convection through the channels, heat of the fins from the base by absorbing the heat generated by the LED module can be dissipated to atmosphere. Accordingly, the LED module can be cooled to some degree.
However, by the provision of the fins and the unidirectional channels defined between the fins, the natural air convection cannot have a sufficient heat exchange with the fins, whereby the heat generated by the LED module cannot be timely dissipated to surrounding atmosphere, and performance of the LED module is accordingly undesirably affected.
What is needed, therefore, is a heat dissipation device for an LED module, which can provide improved heat dissipation efficiency.